Julia Roberts' half-sister died last weekend of an apparent drug overdose, her family announced Monday.

People.com reported that Nancy Motes, 37, was the youngest sister of Julia and actor Eric Roberts.

She was found dead Sunday in Los Angeles, the family said in a statement.

"It is with deep sadness that the family of Nancy Motes ... confirms that she was found dead in Los Angeles yesterday of an apparent drug overdose," the statement said. "There is no official report from the Coroner's office yet. The family is both shocked and devastated."

Julia Roberts, seen at the Palm Springs International Film Festival Awards Gala earlier this month, is mourning with her family Monday after the death of her half-sister Nancy Motes. (Jordan Strauss/Associated Press)

Motes, who once reportedly weighed close to 300 pounds, told the New York Daily News in August 2013 that she was "incredibly hurt and very sad" over "not-so-nice" comments Julia Roberts allegedly made to her over the years about her weight. Gastric bypass surgery in 2010 brought her weight down by almost half. In the interview, she described her relationship with her famous half-sister as "a work in progress."

"It's not going to be fixed overnight, nor do I think it's going to be fixed at this point by me just getting skinny," Motes said. She also said, "I love Julia absolutely, and I have no doubt she loves me."

Motes, who worked as a production assistant on "Glee," was supposed to marry John Dilbeck, a film and TV locations manager, in May, the Daily News said.